diff --git a/heterogeneous_data/multivariate_models_v1_7.ipynb b/heterogeneous_data/multivariate_models_v1_7.ipynb
index f90ab02b012c1a31eb9f8f38d150b67089739116..c1c5b956ab318317be28b0dbde6714d110711d81 100644
--- a/heterogeneous_data/multivariate_models_v1_7.ipynb
+++ b/heterogeneous_data/multivariate_models_v1_7.ipynb
@@ -1673,9 +1673,9 @@
     "## MCVAE\n",
     "The MultiChannel VAE is built by stacking multiple VAEs and allowing the decoding distributions to be computed from every input channel.\n",
     "\n",
-    "Excercise: sketch the Sparse MCVAE. How many (log) alpha parameters do we need?\n",
+    "<img src=\"https://gitlab.inria.fr/epione/flhd/-/raw/master/heterogeneous_data/img/mcvae.svg\" alt=\"img/mcvae.svg\">\n",
     "\n",
-    "<img src=\"https://gitlab.inria.fr/epione/flhd/-/raw/master/heterogeneous_data/img/mcvae.svg\" alt=\"img/mcvae.svg\">\n"
+    "__Excercise__: sketch the Sparse MCVAE with 3 channels.[[solution]](https://gitlab.inria.fr/epione/flhd/-/raw/master/heterogeneous_data/img/sparse_mcvae_3ch.svg)"
    ]
   },
   {